JPH0344996B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device for mitigating the impact that a spreader in a container crane receives during container gripping operations, particularly when there is no dimensional allowance in the corner block portion of the spreader. The present invention relates to a shock absorbing device suitable for.

[Conventional technology]

A conventional shock absorbing device for a spreader, as shown in FIG. 5 and described in Japanese Patent Application Laid-open No. 49-61853, has an elastic body 4 disposed after the mechanism of the twist lock pin 1.
The elastic energy of the elastic body 4 was used to cushion the impact. However, in an actual product, the structure in which the twist lock pin 1 can move up and down by the amount of elasticity of the elastic body means that when hoisting the spreader 13, there will be a situation where the container cannot be lifted by the amount of elasticity of the elastic body 4. When the twist lock pin 1 was pulled, a large force was suddenly applied and there was a risk of breakage.

[Problem that the invention seeks to solve]

Conventional shock mitigation devices place an elastic body after the twist lock pin mechanism to reduce the impact that the spreader receives when the container is gripped, and the twist lock pin also moves up and down by the amount of deformation of the elastic body. When lifting a container, the impact of the twist lock pin is applied while the container is being accelerated, so there is a risk that the twist lock pin may be damaged.

SUMMARY OF THE INVENTION An object of the present invention is to provide a compact shock absorbing device in which a twist lock pin and a shock absorbing device are integrated so that the twist lock pin does not move up and down.

[Means for solving problems]

The above purpose can be achieved by installing a shock mitigation mechanism separately from the twist lock pin mechanism, but since the area that comes into contact with the container is limited to a small area of the corner block, installing a shock mitigation device is necessary. The location is limited to the area around the twist lock pin mechanism. This can be achieved by integrating the shock absorbing device with the twist lock pin.

[Effect]

When the spreader is lowered onto the container during a container gripping operation, the outer sleeves of the corner block portions at the four corners of the spreader are pushed up by the container and the inner sleeves and twist lock pins are fitted into the elongated holes of the container. When the outer sleeve is pushed up by the container, the volume of the hollow cylindrical part made up of the inner and outer sleeves on the circumference of the twist lock pin becomes narrower, and the elastic body placed inside the hollow cylindrical part is compressed. Ru.

The kinetic energy of the spreader is absorbed as compression energy of the elastic body, and when the spreader collides with the container, the impact speed is sufficiently relaxed and no large impact force is generated.
Therefore, the reliability of each device that makes up the spreader is greatly improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. Here, FIG. 1 is a sectional view showing the main structure of the shock mitigation device of the present invention, FIG. 2 is a structural view showing a cross section obtained by rotating FIG. 1 by 90 degrees, and FIG. -A cross-sectional view, FIG. 4 is a functional explanatory diagram of the spreader.

First, the function of the spreader will be briefly explained using FIG. The spreader 13 of the container crane 14 is equipped with a gripping device and is suspended from a trolley 17 running on a boom 15.
It is used to transport containers 19 from container storage sites such as docks and ship holds. The operation of the spreader 13 to grab the container 19 is normally performed as follows. The spreader 13 approaches the container 19 from above, and when it comes within a certain distance, a positioning guide device called a flipper is activated. Then, the spreader 13 is lowered while being guided by the flipper, so that the spreader 13 is placed on the upper surface of the container 19. Next, the twist lock pins of the container gripping device arranged at the four corners of the spreader 13 are rotated to join the container 19 and the spreader 13. In the above operation, the descending speed of the spreader 13 is quite fast, and at the moment the spreader 13 lands on the container 19, a very severe impact load is applied to the container 19 and the spreader 13 due to the inertial force of the spreader 13. This impact load causes the spreader 1 to
Accidents were occurring frequently in which the component equipment in section 3 broke down.

Here, the cargo handling work that is particularly prone to accidents is when transporting the container 19 from the hold of the container ship 21, and the crane driver must visually observe the distance between the spreader 13 in the hold and the container 19 from the operator's cabin 18. The spreader 13 often came into contact with the container at high speed. Therefore,
The present invention is designed to reduce impact loads during cargo handling operations and prevent large impact loads from being applied directly to containers and spreaders.

Next, the configuration of the present invention will be explained using FIGS. 1, 2, and 3. In FIGS. 1 to 3, 1 is inserted into a long hole (not shown) in a container 19 and rotated 90 degrees to create a spreader 1.
2 is an inner sleeve for holding the twist lock pin 1, and 3 forms a hollow cylindrical portion 3a between the inner sleeve 2 and the inside of the elongated hole of the container 19. In contrast to the inner sleeve 2 that enters, the outer sleeve 4 is arranged in a hollow cylindrical part and is configured to touch the outside surface of the elongated hole and move upward by being pushed by the container. 3 is an elastic body compressed by the rise of 3; 5 is a sleeve rotation stopper lever that prevents the inner sleeve 2 from rotating; 6 is a spherical bearing surface that supports the twist lock pin; 7 is attached to the outer sleeve 3; This is a landing detection piece that pushes up the lever of the limit switch 8 when the outer sleeve rises.

Next, the shock mitigation operation will be explained. When the spreader 13 is suspended from the upper surface of the container 19, the twist lock pin 1 and the inner sleeve 2 enter the elongated holes at the four corners of the container and are not subjected to impact, but the outer sleeve 3 collides with the outside surface of the elongated hole. I also received a big shock. As a result, the outer sleeve 3 rises and compresses the elastic body 4. At this time, a part of the impact energy is dissipated as compression energy of the elastic body 4, and the impact force transmitted to the corner block 9 is significantly alleviated. Also, Spretsuda 13 is in container 19.
When the spreader 13 is fully placed on the floor, the landing detection piece 7 pushes up the lever of the limit switch 8, thereby detecting that the spreader 13 has landed on the floor.

According to this embodiment, it is possible to reduce the impact load during container cargo handling in a compact and twist lock pin 1.
It can be reliably alleviated with a structure that does not have the risk of damage.

〔Effect of the invention〕

According to the present invention, it is possible to significantly reduce the impact load received during container cargo handling operations using the spreader, thereby reducing the failure rate of the spreader component equipment and greatly improving reliability.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a shock absorbing device showing an embodiment of the present invention, and FIG.
A vertical cross-sectional view rotated by a degree, Figure 3 is A-A in Figure 1.
Cross-sectional view, Figure 4 is a functional explanatory diagram of the spreader, Figure 5
The figure is a longitudinal cross-sectional view of a conventional impact mitigation device. 1... Twist lock pin, 2... Inner sleeve, 3... Outer sleeve, 3a... Hollow cylindrical part, 4
...Elastic body, 5...Sleeve rotation stopper lever, 6
... Spherical bearing surface, 7 ... Landing detection piece, 8 ... Limit switch, 9 ... Corner block, 13 ...
Spretsuda, 14...Container crane, 15...
...Boom, 16...Hoisting device, 17...Trolley,
18...driver's cabin, 19...container, 20...carrier, 21...container ship.

Claims (1)

[Claims] 1 In the spreader of a container crane that connects the container and the spreader with the twist lock pin of the container gripping device, an inner sleeve that holds the twist lock pin is fitted around the outer periphery of the twist lock pin, and a 1. A shock mitigation device for a spreader, characterized in that an outer sleeve having a hollow cylindrical portion formed therebetween is movably fitted, and an elastic body is disposed in the hollow cylindrical portion.